I just got a Schiit Bifrost and Asgard 2. I'm really impressed at how much better the DT770-80's sound with that combo. I had been using a FiiO E17/E09k combo before. Much better bass control, just the right amount of highs, smooth if a little recessed in the kids. It's a really good combo for these phones. I also have some AKG K712's that sound great with the Schiit stack, but the improvement isn't as obvious as it is with the Beyers...